Field of the Invention
The present invention relates to a closing member and an exhaust structure for a combustion apparatus.
Description of the Background Art
A combustion apparatus, for example, a water heater, a heating apparatus and the like, has a main body that is placed inside of a building. The exhaust gas generated from combustion in such a combustion apparatus is generally discharged through an exhaust pipe (B vent) from a roof of a residential house to the outside thereof.
There are locations where an already-placed exhaust pipe cannot be removed, from a point of view of maintaining appearance of buildings, when this already-placed tank water heater should be replaced with a new instantaneous water heater.
At such a location, a new exhaust tube (a flexible exhaust tube) is inserted into the already-placed exhaust pipe without removing this already-placed exhaust pipe, so that a combustion apparatus can be replaced. It is known that such a new exhaust tube is held using an exhaust adapter disclosed in US 2015/0056903A1. On the other hand, when outside air enters the exhaust pipe through a gap between the exhaust pipe and the exhaust tube on the outside of the building, dew condensation may occur within the exhaust pipe inside the building. Accordingly, it is desired to suppress the outside air from entering through a gap between the exhaust pipe and the exhaust tube on the outside of the building. Also, some exhaust pipes that have been already placed may have openings mainly with diameters of 3 inches and 4 inches. Such opening diameter differences also need to be addressed.